The machining of contour pockets is a common task in the machining of workpieces by a machine tool. Such contour pockets are produced with the aid of a machine tool controlled by a numerical control unit, e.g., by milling a workpiece. In this context, regions of the workpiece surface are machined, which are defined at the start of each instance of contour-pocket machining. Further, typical machining steps for producing a contour pocket then include, for instance, rough drilling, reaming, and finishing.
The defining of the contour pocket may not be a simple task, as soon as the shape of the contour pocket is more complicated than the simplest geometric figures, such as a circle, rectangle, or triangle. Islands may also be left inside the contour pockets, and the borders of the contour pockets may be as complicated as needed.
Conventional numerical control units already offer functions for defining contour pockets. However, these functions do not optimally support the user in achieving his or her objective. In the handbook regarding the software of numerical control unit TNC 426 of the Applicant of the present application, a method is described by which a contour pocket can be defined. To this end, borders of surfaces are defined, which are then rough-worked in a separate cycle. Whether the border describes a pocket or an island depends on the direction and the cutter-radius correction of a border. The contour pocket ultimately formed is then the sum of all pockets minus the sum of all islands. A certain amount of experience is necessary for using this system to define complicated contour pockets, e.g., those made up of several basic shapes. In addition, the contour pocket to be expected can only be assessed in a simulation run after completion of the programming.
It is described in European Published Patent Application No. 0 477 398 that, for the purpose of correcting the cutter radius, complicated workpiece geometries can be produced from more simple base shapes, using set operations (union, intersection, etc.), since then, the cutting-radius correction can already be undertaken on the simpler base shapes.
An aspect of the present invention may provide a method for machining contour pockets, which may allow even inexperienced users to produce contour pockets in a rapid and error-free manner.
An aspect of the present invention may provide a device, which may allow rapid and error-free machining of contour pockets.